Ventilator dependence in critically ill patients with ventilator-associated pneumonia caused by carbapenem-resistant Acinetobacter baumannii: a multicenter observational study

Abstract Background: Ventilator-associated pneumonia (VAP) is a leading cause of morbidity and mortality in intensive care units (ICUs). Carbapenem-resistant Acinetobacter baumannii (CRAB) is one of the key pathogens associated with VAP. Research on ventilator dependence in patients with VAP caused by CRAB remains limited.Methods: In this retrospective multicenter study, we enrolled ICU-admitted patients with VAP caused by CRAB. The status of ventilator dependence was determined on day 21 after initiating ventilator support, and the clinical factors associated with ventilator dependence as well as the differences in treatment outcomes between patients with and without ventilator dependence were investigated. The impact of VAP-onset time, defined as time between hospitalization and VAP onset, on ventilator dependence and mortality was also explored. Results: A total of 274 patients with VAP caused by CRAB were analyzed. The overall ventilator-dependence rate on day 21 was 63.5% (174/274). Patients with ventilator dependence had longer ICU stays (28.5 [interquartile range (IQR) 21–43] days vs. 16.0 (IQR 12–21) days, P<0.001) and higher day 28 mortality rates (17.2% vs. 5%, P=0.003). Clinical factors associated with ventilator dependence were advanced age (adjusted odds ratio [aOR] 1.02, 95% confidence interval [CI] 1.00–1.04), higher Acute Physiology and Chronic Health Evaluation (APACHE) II score (aOR 1.04, 95% CI 1.00–1.08), PaO2/FIO2 (PF) ratio <200 (aOR 2.194, 95% CI 1.20–3.99), and late onset VAP (6–10 days: aOR 2.28, 95% CI 1.04–4.99; >10 days: aOR 3.92, 95% CI 1.86–8.29). Patients with late onset VAP had higher mortality rates. Conclusions: Advanced age, higher APACHE II score, PF ratio<200, and late onset VAP were independent factors associated with ventilator dependence in patients with VAP caused by CRAB. Patients with ventilator dependence and late onset VAP were associated with higher mortality rates. Trial registration: This is an observational study; therefore, it has not been registered.